lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230718075708.958094-8-msp@baylibre.com>
Date:   Tue, 18 Jul 2023 09:57:03 +0200
From:   Markus Schneider-Pargmann <msp@...libre.com>
To:     Marc Kleine-Budde <mkl@...gutronix.de>,
        Chandrasekar Ramakrishnan <rcsekar@...sung.com>,
        Wolfgang Grandegger <wg@...ndegger.com>
Cc:     Vincent MAILHOL <mailhol.vincent@...adoo.fr>,
        Simon Horman <simon.horman@...igine.com>,
        "David S . Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>, linux-can@...r.kernel.org,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Julien Panis <jpanis@...libre.com>,
        Markus Schneider-Pargmann <msp@...libre.com>
Subject: [PATCH v5 07/12] can: m_can: Cache tx putidx

m_can_tx_handler is the only place where data is written to the tx fifo.
We can calculate the putidx in the driver code here to avoid the
dependency on the txfqs register.

Signed-off-by: Markus Schneider-Pargmann <msp@...libre.com>
Reviewed-by: Simon Horman <simon.horman@...igine.com>
---
 drivers/net/can/m_can/m_can.c | 8 +++++++-
 drivers/net/can/m_can/m_can.h | 3 +++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 6a815812ae38..45e8afb1b795 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1482,6 +1482,10 @@ static int m_can_start(struct net_device *dev)
 
 	m_can_enable_all_interrupts(cdev);
 
+	if (cdev->version > 30)
+		cdev->tx_fifo_putidx = FIELD_GET(TXFQS_TFQPI_MASK,
+						 m_can_read(cdev, M_CAN_TXFQS));
+
 	return 0;
 }
 
@@ -1771,7 +1775,7 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 		}
 
 		/* get put index for frame */
-		putidx = FIELD_GET(TXFQS_TFQPI_MASK, txfqs);
+		putidx = cdev->tx_fifo_putidx;
 
 		/* Construct DLC Field, with CAN-FD configuration.
 		 * Use the put index of the fifo as the message marker,
@@ -1805,6 +1809,8 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 
 		/* Enable TX FIFO element to start transfer  */
 		m_can_write(cdev, M_CAN_TXBAR, (1 << putidx));
+		cdev->tx_fifo_putidx = (++cdev->tx_fifo_putidx >= cdev->can.echo_skb_max ?
+					0 : cdev->tx_fifo_putidx);
 
 		/* stop network queue if fifo full */
 		if (m_can_tx_fifo_full(cdev) ||
diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
index d0c21eddb6ec..548ae908ac4e 100644
--- a/drivers/net/can/m_can/m_can.h
+++ b/drivers/net/can/m_can/m_can.h
@@ -102,6 +102,9 @@ struct m_can_classdev {
 	u32 tx_max_coalesced_frames_irq;
 	u32 tx_coalesce_usecs_irq;
 
+	// Store this internally to avoid fetch delays on peripheral chips
+	int tx_fifo_putidx;
+
 	struct mram_cfg mcfg[MRAM_CFG_NUM];
 };
 
-- 
2.40.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ